Efficient Implementation of the Random Phase Approximation with Domain-based Local Pair Natural Orbitals

TL;DR

This paper introduces an efficient DLPNO-based implementation of RPA that maintains high accuracy in total correlation energy calculations, enabling cost-effective and precise molecular energy computations for large systems.

Contribution

The paper presents a novel, optimized DLPNO-RPA method that significantly reduces computational costs while preserving near-canonical accuracy in molecular energy calculations.

Findings

Achieves 99.9% accuracy in correlation energy compared to canonical RPA.

Successfully computes basis set-converged binding energies for large molecules.

Demonstrates potential for routine use of RPA in molecular quantum chemistry.

Abstract

We present an efficient implementation of the random phase approximation (RPA) for molecular systems within the domain-based local pair natural orbital (DLPNO) framework. With optimized parameters, DLPNO-RPA achieves approximately 99.9% accuracy in the total correlation energy compared to a canonical implementation, enabling highly accurate reaction energies and potential energy surfaces to be computed while substantially reducing computational costs. As an application, we demonstrate the capability of DLPNO-RPA to efficiently calculate basis set-converged binding energies for a set of large molecules, with results showing excellent agreement with high-level reference data from both coupled cluster and diffusion Monte Carlo. This development paves the way for the routine use of RPA-based methods in molecular quantum chemistry.